Rate Of Residual Renal Function Decline Research Articles

Intra-abdominal pressure and residual renal function decline in peritoneal dialysis: a threshold-based investigation

Background The potential impact of elevated intra-abdominal pressure (IAP) on residual renal function (RRF) has not been determined. The objective of this study was to investigate the relationship between IAP and the rate of RRF decline in newly initiated peritoneal dialysis (PD) patients, and to identify the optimal IAP threshold value for delaying the deterioration of RRF. Methods A cohort of 62 newly initiated PD patients who completed both 6- and 12-month follow-up evaluations was obtained using the Durand method. A logistic regression model was used to identify variables associated with a rapid decline in RRF. Receiver operating characteristic (ROC) curves were generated to determine the optimal threshold value. Another retrospective cohort analysis was performed to validate the identified critical value. Results For each 1 cmH2O increase in IAP, the risk of a rapid decline in the RRF increased by a factor of 1.679. Subsequent analysis revealed that patients in the high IAP group had more significant decreases in residual renal estimated glomerular filtration rate (eGFR) (Z = −3.694, p < 0.001) and urine volume (Z = −3.121, p < 0.001) than did those in the non-high IAP group. Furthermore, an IAP ≥15.65 cmH2O was a robust discriminator for the prediction of the rate of RRF decline. Conclusion Patients in the high IAP group experienced a more rapid decline in RRF. Additionally, an optimal critical pressure of 15.65 cmH2O was identified for predicting the rate of RRF decline. IAP, as one of the factors contributing to the rapid decline in RRF in the first year of PD, should be given due attention.

Nutritional intervention in end-stage renal disease: a clinical trial study.

Chronic kidney disease is a global health problem, and end-stage renal disease (ESRD) has a major impact on patients' quality of life and prognoses. However, studies on individualized nutritional therapy for patients with ESRD need more complementary evidence. A clinical study was conducted based on a small population. It included patients with ESRD who underwent dialysis treatment in the Taicang Hospital Department of Nephrology, Soochow University, China, between January 2019 and December 2021. According to the randomized number table method, patients were divided into the nutritional treatment group (NIG) and the non-nutritional intervention control group (NNIG). There were 84 patients in the NIG and 92 patients in the NNIG. This study analyzed the changes in residual renal function (RRF) and indicators of blood and kidney function in ESRD with personalized nutritional therapy. The results show that nutritional interventions for ESRD are effective in reducing the rate of decline in RRF and improving indicators of blood and kidney function in patients with ESRD. It was also found that patients with diabetes mellitus gained fewer health benefits per unit of RRF improvement with individualized nutritional therapy. This study provides important information about the treatment effects and factors associated with individual nutritional interventions in a population with ESRD. These results contribute to a better understanding of the effects of nutritional therapy in ESRD and provide a basis for managing it. Further studies should focus on specific populations and potential interventions to improve patient prognosis.

Association of Urinary Dickkopf-3 with Residual Renal Function Decline in Patients Undergoing Peritoneal Dialysis.

Background and Objectives: Urinary levels of dickkopf-3 (DKK-3) are associated with poor renal survival in patients with non-dialytic chronic kidney disease. However, it remains unknown whether urinary DKK-3 levels can predict residual renal function (RRF) decline in patients undergoing peritoneal dialysis (PD). Therefore, we investigated the correlation between urinary levels of DKK-3 and the subsequent rate of RRF decline in PD patients. Materials and Methods: This study included 36 PD patients who underwent multiple peritoneal equivalent tests during 2011–2021. The relationship between baseline clinical characteristics and the subsequent annual rate of Kt/V decline was investigated. Results: The annual rate of renal Kt/V decline was 0.29 (range: 0.05–0.48), which correlated with renal Kt/V (r = 0.55, p = 0.0005) and 24 h urinary DKK-3 excretion (r = 0.61, p < 0.0001). Similarly, 24 h urinary DKK-3 excretion (β = 0.44, p = 0.0015) and renal Kt/V (β = 0.38, p = 0.0059) were independently associated with the annual rate of renal Kt/V decline in multivariate analyses. Conclusions: Urinary DKK-3 assessment may help identify PD patients at a high risk of RRF decline.

A Fast Decline of Residual Renal Function in the First Year is a Predictor for Early Withdrawal from Peritoneal Dialysis in Non-Diabetic Patients

Background/Aims: Little is known about the relationship between residual renal function (RRF) decline in early period and survival in non-diabetic peritoneal dialysis (PD) patients. Methods: A total of 567 non-diabetic patients who began PD from January 1, 2005 to June 30, 2013 was investigated. The rate of RRF decline was determined by the “slope of the trend equation” of serial RRFs. A composite end-point of all-cause mortality and conversion to hemodialysis (HD) was used, survival status was censored on June 30, 2016. Results: The median of “the slope of RRF decline equation” was 0.308 (0.001-2.111) ml/min/1.73 m2/ month. In the median follow-up period of 43 months (range 12 to 120 months), 65 (11.5%) patients died, 90 (15.9%) patients converted to HD and 171 (30.2%) patients received kidney transplantation. Multivariate linear regression showed male, high baseline RRF, high baseline peritoneal Kt/V urea, low serum albumin and low uric acid were independently associated with the rate of RRF decline in the first year of PD. Multivariate Cox models revealed that RRF decline in the first year remained a predictor for composite end-point (HR, 2.74, 95% CI, 1.53 to 4.90, P=0.001). The patients were divided into high RRF decline group (> 0.308ml/ min/1.73m2/month) and low RRF decline group (≤0.308 ml/min/1.73m2/month). In the first three years of PD, the rate of end-point events was higher in high RRF decline group (23.2%) than that in low RRF decline group (11.0%) (P< 0.001). There were 189 patients in low RRF decline group and 171 patients in high RRF decline group maintaining PD for more than 3 years, in a median follow-up of 54 months (range 37 to 120 months), the survival rate was 30.9% in high RRF decline group and 46.4% in low RRF decline group (P=0.883). In high RRF decline group, there were 92 patients reaching composited end-point and 112 patients maintaining PD; multivariate Cox model showed high peritoneal Kt/V urea after 1 year of PD and high albumin level were protective factors (HR, 0.29, 95% CI, 0.13 to 0.61, P= 0.001; HR, 0.94, 95% CI, 0.90-0.99, P=0.022, respectively), while fast RRF decline remained risk factor for composite end-point (HR, 3.28, 95% CI,1.48-7.31, P=0.004). Conclusion: A faster RRF decline in the first year was a predictor for all-cause mortality and conversion to HD in non-diabetic PD patients, mainly in the first three year. For patients with faster RRF decline, increasing PD dose was effective to improve survival.

The protective effect of different dialysis types on residual renal function in patients with maintenance hemodialysis: A systematic review and meta-analysis.

Residual renal function (RRF) is an important determinant of mortality and morbidity in patients undergoing hemodialysis. Different dialysis types may have different effects on RRF. We therefore conducted this meta-analysis to examine the RRF protective effect of different dialysis types for hemodialysis patients. A systematic search was performed on PubMed, EMbase, Web of Science, Chinese Biomedical Literature Database, Wanfang database, and China National Knowledge Infrastructure for randomized controlled trials and cohort studies. Dialysis types included low-flux hemodialysis (LFHD), high-flux hemodialysis (HFHD), hemodiafiltration (HDF), and hemodialysis and hemoperfusion (HD+HP). The mean of endogenous creatinine clearance rate (CCR) and urea clearance rate (Curea), or urine volume was used to estimate RRF [95% confidence interval (95% CI), 6.05-16.80]. There were 12 articles involving 1224 patients, including 11 random controlled trials and 1 cohort study. Meta-analysis showed that the RRF protective effect of HFHD [mean difference (MD) = 1.48, 95% CI (2.11 to 0.86), P < .01] and HD+HP [MD = 0.41, 95% CI (0.69 to 0.12), P = .005] was better than that of LFHD, and the RRF decline rate was the lowest in HFHD group [MD = 0.13, 95% CI (0.17 to 0.09), P < .01]. Descriptive analysis showed that HDF could better protect RRF when compared with LFHD. However, there was no consistency among other interventions when removing LFHD due to limited data. For patients undergoing maintenance hemodialysis, the HFHD, HD+HP and HDF may better protect RRF, compared with LFHD.

Baseline and Time-Averaged Values Predicting Residual Renal Function Decline Rate in Japanese Peritoneal Dialysis Patients.

Residual renal function (RRF) is a strong prognostic factor of morbidity and mortality in patients undergoing peritoneal dialysis (PD). We determined predictors of the RRF rate of decline using both baseline values and time-averaged ones. We retrospectively analyzed 94 patients being treated with PD at the Japanese Red Cross Medical Center. The decline rate of RRF was calculated by a diminution in the weekly renal Kt/V between the first and last follow up divided by follow-up years. The mean follow-up period was 2.28 years, and the mean decline rate of weekly renal Kt/V was 0.25 per year. A multivariate analysis using baseline parameters identified dialysis-to-plasma ratios of creatinine at 4 h (P = 0.02), urinary protein (P = 0.02), and mean blood pressure (MBP) (P < 0.01) as being positively associated with the RRF rate of decline, while the use of angiotensin converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) had a negative correlation (P = 0.03). When using time-averaged values as independent variables, a lower weekly total renal Kt/V (P < 0.0001), higher urinary protein (P < 0.0001), and higher MBP (P = 0.04) independently predicted a faster RRF rate of decline. We demonstrated that PD patients with a lower MBP and lower urinary protein both at baseline and throughout their PD duration had a slower RRF rate of decline. We recommend strict control of blood pressure and anti-proteinuric therapy for PD patients.

U-shaped relationship between uric acid and residual renal function decline in continuous ambulatory peritoneal dialysis patients.

There is little information on the relationship between uric acid (UA) and residual renal function (RRF) in continuous ambulatory peritoneal dialysis (CAPD). The aim of this research is to study the influence of UA on RRF decline in CAPD patients. A retrospective observational cohort study of 304 patients who started CAPD without anuria between 2001 and 2010 was conducted at a single medical center. The outcomes measured in the study included the rate of RRF decline and anuria. A multiple ordinal logistic regression model with backward elimination was conducted to determine the independent factors of the slope of RRF decline. A Cox proportional hazard model was conducted to determine the independent variables of time to anuria. The average rate of RRF decline was -0.12 ± 0.22 mL/min per month. Multivariate analysis showed that lower UA group (<0.372 mmol/L), higher UA group (≧0.421 mmol/L), male gender, diabetes mellitus (DM), the use of calcium channel blocker (CCB), and RRF at baseline were linked positively with the rate of RRF decline; on the other hand, independence in dialysate exchanges and BUN were negatively associated with the risk of RRF decline. In addition, male gender, DM, diuretics, and CCB were associated with a higher risk of progression to anuria, whereas 24-h urine amount at baseline conferred a protective role in the development of anuria. A U-shaped relationship was found between UA levels and the rate of RRF decline in patients on CAPD, with a faster decline rate in those of higher and lower UA groups.

Excessive Weight Gain during the First Year of Peritoneal Dialysis Is Associated with Inflammation, Diabetes Mellitus, and a Rapid Decrease in Residual Renal Function.

ObjectivesSignificant weight gain is a potential problem in most patients starting peritoneal dialysis (PD); however, few studies have explored the clinical effects of increased body weight (BW) in these patients. We evaluated the effect of excess weight gain during the first year after PD on residual renal function (RRF).MethodsA total of 148 incident PD patients were analyzed in a longitudinal observational study. The mean duration of follow-up was 23.8 months. RRF was measured at baseline (within 1 month of starting PD) and thereafter at 6-month intervals for 2–3 years or until loss of RRF. BW was measured at the time of RRF measurement, and excess weight gain was defined as a BW increase over the median value (3.0%).ResultsThe median 1-year increase in BW was 2.3kg (IQR, 1.01–4.58) or 3.0% (IQR, 1.13–5.31). The mean slope of RRF decline was –0.068 ± 0.053 mL/min/month/1.73m2, and RRF loss developed in 48 patients at a mean follow-up time of 19.4 ± 6.8 months. Patients with BW increases > 3.0% showed significantly increased RRF decline rate compared to those without excess weight gain (p<0.001), and the BW increase (%/year) correlated significantly with higher hs-CRP levels and RRF decline rate. High systolic blood pressure, diabetes, large amount of proteinuria and excess BW gain significantly influenced the RRF decline rate. Also, it increased the risk of RRF loss by 4.17-fold (95% confidence intervals, 1.87–9.28; p<0.001).ConclusionsExcess weight gain during the first year of PD was closely linked to systemic inflammation, diabetes and rapid decline in RRF.

Low Serum Bicarbonate Predicts Residual Renal Function Loss in Peritoneal Dialysis Patients.

Low residual renal function (RRF) and serum bicarbonate are associated with adverse outcomes in peritoneal dialysis (PD) patients. However, a relationship between the 2 has not yet been determined in these patients. Therefore, this study aimed to investigate whether low serum bicarbonate has a deteriorating effect on RRF in PD patients.This prospective observational study included a total of 405 incident patients who started PD between January 2000 and December 2005. We determined risk factors for complete loss of RRF using competing risk methods and evaluated the effects of time-averaged serum bicarbonate (TA-Bic) on the decline of RRF over the first 3 years of dialysis treatment using generalized linear mixed models.During the first 3 years of dialysis, 95 (23.5%) patients became anuric. The mean time until patients became anuric was 20.8 ± 9.0 months. After adjusting for multiple potentially confounding covariates, an increase in TA-Bic level was associated with a significantly decreased risk of loss of RRF (hazard ratio per 1 mEq/L increase, 0.84; 0.75–0.93; P = 0.002), and in comparison to TA-Bic ≥ 24 mEq/L, TA-Bic < 24 mEq/L conferred a 2.62-fold higher risk of becoming anuric. Furthermore, the rate of RRF decline estimated by generalized linear mixed models was significantly greater in patients with TA-Bic < 24 mEq/L compared with those with TA-Bic ≥ 24 mEq/L (−0.16 vs −0.11 mL/min/mo/1.73 m2, P < 0.001).In this study, a clear association was found between low serum bicarbonate and loss of RRF in PD patients. Nevertheless, whether correction of metabolic acidosis for this indication provides additional protection for preserving RRF in these patients is unknown. Future interventional studies should more appropriately address this question.

Changes in echocardiographic parameters according to the rate of residual renal function decline in incident peritoneal dialysis patients.

Residual renal function (RRF) is associated with left ventricular (LV) hypertrophy as well as all-cause and cardiovascular (CV) mortality in patients with end-stage renal disease. However, no studies have yet examined the serial changes in echocardiographic findings according to the rate of RRF decline in incident dialysis patients. A total of 81 patients who started peritoneal dialysis (PD) between 2005 and 2012 at Yonsei University Health System, Seoul, South Korea, and who underwent baseline and follow-up echocardiography within the first year of PD were recruited. Patients were dichotomized into "faster" and "slower" RRF decline groups according to the median values of RRF decline slope (-1.60 mL/min/y/1.73 m(2)). Baseline RRF and echocardiographic parameters were comparable between the 2 groups. During the first year of PD, there were no significant changes in LV end-diastolic volume index (LVEDVI), left atrial volume index (LAVI), or LV mass index (LVMI) in the "faster" RRT decline group, while these indices decreased in the "slower" RRT decline group. The rate of RRF decline was a significant determinant of 1-year changes in LVEDVI, LAVI, and LVMI. The linear mixed model further confirmed that there were significant differences in the changes in LVEDVI, LAVI, and LVMI between the 2 groups (P = 0.047, 0.048, and 0.001, respectively). During a mean follow-up duration of 31.9 months, 4 (4.9%) patients died. Compared with the "slower" RRF decline group, CV composite (20.29/100 vs 7.18/100 patient-years [PY], P = 0.098), technique failure (18.80/100 vs 4.19/100 PY, P = 0.006), and PD peritonitis (15.73/100 vs 4.95/100 PY, P = 0.064) developed more frequently in patients with "faster" RRF decline rate. On multivariate Cox regression analysis, patients with "faster" RRF decline rate showed 4.82-, 4.44-, and 7.37-fold higher risks, respectively, for each clinical outcome. Preservation of RRF is important for conserving cardiac performance, resulting in an improvement in clinical outcomes of incident PD patients.

Inflammation and Myocardial Damage Markers Influence Loss of Residual Renal Function in Peritoneal Dialysis Patients

Residual renal function (RRF) has been identified as the most important component in dialysis adequacy and has a strong effect on clinical outcomes. This justifies any effort in understanding the mechanism behind the preservation or decline in RRF. The aim of this study was to analyze the possible association of components of cardio-renal syndrome with the rate of decline in RRF. A retrospective cohort study was performed in a group of prevalent adult patients on continuous ambulatory peritoneal dialysis (CAPD). Patients were analyzed at baseline and after a 30-month follow-up. Evaluations included measurements of residual renal function, dialysis adequacy parameters, cardiovascular comorbidity, and measurements of biochemical markers of cardiovascular disease (CVD) and inflammation, as well as resting electrocardiography. We included 129 patients in the study who were divided into groups according to loss of RRF, considering the cut-off point as 100 mL/day of 24 h urine volume. At baseline, there were no differences between groups: patients who lost RRF showed low values of 24 h urine volume, higher levels of systolic blood pressure, N-terminal pro-brain natriuretic peptide (NT-proBNP), C-reactive protein (CRP), IL-6, and low values of serum albumin. In the multivariate analysis, age, albumin, CRP, and NT-proBNP were significant risk factors for the loss of RRF. Data indicate a close relationship between heart and kidney function where chronic kidney disease (CKD) affects and is an effect of, heart function, indicative of a bi-directional influence that leads to a vicious cycle, promoting deleterious effects on both systems.

Effect of Peritoneal Dialysis Modality on the 1-Year Rate of Decline of Residual Renal Function

PurposeThe effect of different peritoneal dialysis (PD) modalities on the decline in residual renal function (RRF) is unclear due to inconsistencies among studies. In particular, the effect of automated peritoneal dialysis (APD) modalities [continuous cyclic peritoneal dialysis (CCPD) and nightly intermittent peritoneal dialysis (NIPD)] on RRF has not been examined in a large cohort.Materials and MethodsWe conducted a single-center retrospective study to investigate the association between PD modalities and decline in RRF in 142 incident PD patients [34 on CCPD, 36 on NIPD, and 72 on continuous ambulatory peritoneal dialysis (CAPD)]. RRF was measured within 2 months from PD start and at 1 year after PD initiation.ResultsThe RRF at 1 year after PD initiation was 1.98±2.20 mL/min/1.73 m2 in CCPD patients and 3.63±3.67 mL/min/1.73 m2 in NIPD patients, which were moderately lower than 4.23±3.51 mL/min/1.73 m2 in CAPD patients (p=0.064). Moreover, there was no significant difference in the 1-year rate of decline of RRF between CCPD and NIPD patients, although APD patients had a faster 1-year RRF decline rate than CAPD patients (CCPD and NIPD vs. CAPD: -45.68 and -36.69 vs. 1.17%/year, p=0.045). APD was associated with a more rapid decline in RRF in patients with end-stage renal disease undergoing PD, although multivariate analysis attenuated the significance of this finding (β=-31.50; 95% CI, -63.61 to 0.62; p=0.052).ConclusionOur results suggest that CAPD might be more helpful than APD for preserving RRF during the first year of dialysis therapy, although there was no significant difference in the 1-year rate of decline of RRF between the two APD modalities.

A Combination of Biocompatible Peritoneal Dialysis Solutions and Residual Renal Function, Peritoneal Transport, and Inflammation Markers: A Randomized Clinical Trial

The benefits of biocompatible peritoneal dialysis (PD) fluids, particularly for residual renal function (RRF), are controversial. Moreover, the clinical effects of a PD regimen consisting of different biocompatible PD fluids have not been fully established. Prospective, randomized, controlled, open-label study. Patients with end-stage kidney disease newly started on continuous ambulatory PD therapy (N = 150). A 12-month intervention with 3 biocompatible PD fluids (a neutral-pH, low glucose degradation product, 1.5% glucose solution; a solution with 1.1% amino acid; and a fluid with 7.5% icodextrin) or conventional PD fluid. The primary outcome was change in RRF and daily urine volume. Secondary outcomes were peritoneal transport and inflammation markers. RRF, daily urine volume, serum and dialysate cytokine levels. RRF(3.24 ± 1.98 vs 2.88 ± 2.43 mL/min/1.73 m(2); P = 0.9) and rate of decline in RRF (-0.76 ± 1.77 vs -0.91 ± 1.92 mL/min/1.73 m(2) per year; P = 0.6) did not differ between the biocompatible- and conventional-PD-fluid groups. However, patients using the biocompatible PD fluids had better preservation of daily urine volume (959 ± 515 vs 798 ± 615 mL/d in the conventional group, P = 0.02 by comparison of difference in overall change by repeated-measures analysis of variance). Their dialysate-plasma creatinine ratio at 4 hours was higher at 12 months (0.78 ± 0.13 vs 0.68 ± 0.12; P = 0.01 for comparison of the difference in overall change by repeated-measures analysis of variance). They also had significantly higher serum levels of adiponectin and overnight spent dialysate levels of cancer antigen 125, adiponectin, and interleukin 6 (IL-6). No differences between the 2 groups were observed for serum C-reactive protein and IL-6 levels. Unblinded, relatively short follow-up; no formal sample-size calculations. Use of a combination of 3 biocompatible PD fluids for 12 months compared with conventional PD fluid did not affect RRF, but was associated with better preservation of daily urine volume. The biocompatible PD fluids also lead to changes in small-solute transport and an increase in dialysate cancer antigen 125, IL-6, adiponectin, and systemic adiponectin levels, but have no effect on systemic inflammatory response. The clinical significance of these changes, while of great interest, remains to be determined by further studies.

Presence of Peripheral Arterial Disease Predicts Loss of Residual Renal Function in Incident CAPD Patients

Accelerated cardiovascular disease (CVD), including peripheral arterial disease (PAD), is very common in patients with end-stage renal disease. Residual renal function (RRF) is a strong predictor of patient survival that is suggested to be linked to the degree of CVD. However, the relationship between PAD and decline in RRF has not previously been measured. We studied incident continuous ambulatory peritoneal dialysis patients from Peking University Third Hospital. An ankle brachial index of less than 0.9 was used to diagnose PAD. Residual renal function (RRF) was determined as the mean of 24-hour urea and creatinine clearances (glomerular filtration rate). The Cox proportional hazards model was used to identify factors predicting loss of RRF. The study included 86 patients (age: 61 ± 14 years; men: 51%), 23 of whom had PAD at baseline. Mean follow-up was 19 months (median: 18 months; range: 6 - 30 months). In univariate analysis, baseline PAD, peritonitis during follow-up, inflammation (C-reactive protein), serum uric acid, Ca×P, and serum phosphate were all significantly associated with a greater-than-50% decrease in RRF during follow-up. In multivariate analysis, only baseline PAD, Ca×P, and peritonitis were independently associated with a decline in RRF. Our study suggests that PAD may be a clinically important marker of CVD predicting the loss of RRF. It remains to be determined whether interventions aimed at decreasing PAD may also improve renal vascular status and thus slow the rate of RRF decline.

Left Ventricular Diastolic Dysfunction as a Predictor of Rapid Decline of Residual Renal Function in Patients with Peritoneal Dialysis

The aim of this study was to evaluate whether diastolic dysfunction at the start of dialysis could influence renal and cardiovascular survival rates in 82 patients undergoing peritoneal dialysis. Diastolic dysfunction was determined using left ventricular hypertrophy, the ratio of early peak transmitral inflow velocity to peak diastolic mitral annular velocity (E/E'), and left atrial volume index (LAVI). Residual renal function (RRF) was measured with 24-hour urine collections at baseline (within 1 month of beginning peritoneal dialysis) and thereafter at 6-month intervals for 2 years. To evaluate the long-term prognostic significance of diastolic dysfunction, the 4-year cardiac event-free survival was also evaluated. The median slope of RRF decline was -0.07 mL/min/mo/1.73 m(2). Forty-five patients (54.9%) with rapid RRF declines (< -0.07 mL/min/mo/1.73 m(2)) had a higher prevalence of diabetes and eccentric left ventricular hypertrophy, as well as significantly elevated E/E' ratios and LAVIs. There was a close relationship between baseline E/E' ratio (r = -0.221, P = .048), LAVI (r = -0.276, P = .015), and RRF decline rate, and both E/E' > 15 (odds ratio, 3.61; 95% confidence interval, 1.07-12.12) and LAVI > 32 mL/m(2) (odds ratio, 3.54; 95% confidence interval, 1.08-11.58) were significant independent predictors of the loss of RRF. Furthermore, E/E' > 15 also provided additional prognostic value in predicting future cardiac events (hazard ratio, 6.74; 95% confidence interval, 1.07-12.12; P = .023). Left ventricular diastolic dysfunction may be a significant predictor of rapid decline in RRF and adverse cardiac outcomes in patients starting peritoneal dialysis.

Nephrology literature watch

Nephrology literature watch

Rate of decline of residual renal function is associated with all-cause mortality and technique failure in patients on long-term peritoneal dialysis

Residual renal function (RRF) at the initiation of peritoneal dialysis (PD) therapy can predict patient outcome. However, RRF declines with time at variable rates in different patients. This study was performed to compare the impact of baseline RRF and the rate of RRF decline on patient survival and on death-censored technique survival after initiation of long-term PD. We enrolled 270 patients with sufficient urine amount (daily urine volume >100 mL) from a medical centre in North Taiwan who began PD between January 1996 and December 2005 and followed them until December 2007. The study population was stratified by the decline rate of RRF into a fast, intermediate and slow decline group. The Kaplan-Meier survival analysis was used to determine patient survival and technique survival. The Cox regression model was used to identify factors associated with patient outcome. The proportional odds polychotomous logistic regression model was used to identify variables associated with rapid decline of RRF. During an average follow-up period of 45 months, 50 (18.5%) deaths, 67 (24.8%) death-censored technique failures (transfer to haemodialysis) and 43 (15.9%) renal transplantations occurred. The median rate of RRF decline was 0.885 mL/min/1.73 m(2) per year. Survival analysis showed that patients with fast RRF decline had worse survival and increased risk of technique failure. The multivariate Cox regression model confirmed that the rate of RRF decline was an independent factor associated with patient and technique survival and was a more powerful prognostic factor than basal RRF. Variables associated with a rapid decline of RRF were larger body mass index, presence of diabetes, prior history of congestive heart failure, use of diuretics, peritonitis episodes and hypotensive events. Our data indicate that the rate of decline of RRF is a more powerful prognostic factor than baseline RRF associated with all-cause mortality and technique failure in patients on long-term PD. To prevent accelerated loss of RRF, it is imperative that every effort be made to avoid overdiuresis, peritonitis and hypotensive episodes, especially in those with diabetes, obesity and congestive heart failure.

Disordered mineral metabolism is not a risk factor for loss of residual renal function in dialysis patients

Recent studies showed that mineral metabolism disorders are associated with renal function loss in pre-dialysis patients, but their effects in dialysis patients are less well established. We examined associations between parameters of mineral metabolism and loss of residual renal function (RRF) in dialysis patients. We included 1468 incident haemodialysis (HD) and peritoneal dialysis (PD) patients who were not anuric at dialysis initiation from NECOSAD, a prospective multicentre cohort study. We studied the effects of plasma calcium, phosphorus, calcium-phosphorus product and intact PTH concentrations on loss of RRF. Cox regression models were applied to calculate relative risks of total loss of RRF, defined as anuria during the first 3 years of dialysis. The rate of decline of RRF over time was calculated using general linear mixed models. The mean (SD) age was 59 (15), 62% were men and 59% were treated with HD. We found that both HD and PD patients with the highest phosphorus (P < 0.0001) and calcium-phosphorus product (P < 0.0001) levels had the lowest baseline residual glomerular filtration rate (rGFR) values. During follow-up, 136 HD (15%) and 67 PD patients (12%) became anuric. After adjustment for baseline rGFR, there were no significant associations between parameters of mineral metabolism and the risk of becoming anuric. There were also no differences in the rate of decline in RRF between categories of plasma concentrations. Disordered mineral metabolism was neither associated with the risk of becoming anuric, nor with the rate of decline in RRF in dialysis patients. Differences in decline were mainly attributable to the baseline rGFR value.

The effect of coronary angiography on residual renal function in patients on peritoneal dialysis

The risk of intravascular radiocontrast to residual renal function (RRF) in patients on peritoneal dialysis (PD) remains largely unknown. This study sought to estimate the effect of coronary angiography on RRF in patients on PD. All patients at the VA Pittsburgh Healthcare System and University of Pittsburgh who underwent coronary angiography between 1993 and 2005 while on PD and who had RRF measured prior to angiography were identified retrospectively. For patients without a postprocedure RRF recorded, medical records were reviewed to determine whether anuria had developed. The longer-term rate of loss of RRF among cases was compared with a composite rate of decline in RRF among cases before angiography and matched controls. Twenty-nine patients with a mean preprocedure RRF of 4.4+/-3.2 ml/min/1.73m(2) were evaluated. Of these patients, 23 (79%) had postangiography RRF assessments (mean clearance 3.4+/-3.0 ml/min/1.73m(2)). One of the remaining six patients definitely became permanently anuric following angiography, one was lost to follow-up, and there was no postprocedure RRF assessment in four others. The rate of decline in RRF in the cases was similar to the composite rate (0.07 ml/min/1.73m(2)/month vs. 0.09 ml/min/1.73m(2)/month, p=0.53) The risk for permanent anuria in patients on PD undergoing coronary angiography appears to be quite small. Patients who do not develop anuria following coronary angiography have the same gradual rate of loss of RRF as other patients on PD. Providers should be vigilant in protecting RRF in patients on PD undergoing coronary angiography.

Impact of Residual Renal Function on Dialysis Adequacy in Paediatric CAPD Patients

This study was designed to determine the impact of residual renal function (RRF) on dialysis adequacy indices and clinical outcome parameters in paediatric CAPD patients. Seventeen children on CAPD were included. Residual renal function was described by residual diuresis (UO: urine output), residual renal solute clearances [RR.KT/V (residual renal KT/V), RR.Ccr (residual renal creatinine clearance) and GFR (glomerular filtration rate)]. Pearson's correlation coefficients and multiple linear regression analysis were used in statistical analysis. Mean W.KT/V (weekly KT/V) vas 1.97±0.6 and mean T.Ccr (total Ccr) was 56±32 L/week/1.73 m2. Both of these indices were found to be strongly correlated with RRF (GFR, UO, RR.KT/V and RR.Ccr) (p<0.001), but not with peritoneal solute clearances. W.KT/V was found to be influenced essentially by RR.KT/V (p<0.001) and also dialysate fill volume (DV) (p<0.01). T.Ccr was influenced primarily by RR.Ccr (p<0.001) and serum cr levels (p<0.05). In addition significant positive correlations were detected between serum albumin, haemoglobin (Hb), haematocrit (Htc) levels and residual diuresis (p<0.05) and a significant negative correlation was found between mean blood pressure and residual diuresis (p<0.05). It was concluded that the mean values of W.KT/V and T.Ccr were heavily influenced by RRF. Almost all variations in W.KT/V and T.Ccr represented changes in RRF. In addition, anaemia, hypertension and hypoalbuminaemia, which are known as clinical criteria of inadequate dialysis, were found to be influenced by residual diuresis. Thus one of the goals of paediatric nephrologists must be the preservation of renal reserve. Since the rate of decline in RRF was significantly lower in CAPD, it should be the first choice of long-term maintenance dialytic therapy for children who have residual renal reserve.